To extend the time during which one can operate a portable electronic device on battery power, engineers typically design the device to consume as little power as possible while operating on batteries. For example, engineers design laptop computers and personal digital assistants (PDAs) to enter a lower-power mode, such as a sleep or standby mode, after a predetermined period of operator inactivity. When the laptop or PDA detects user activity (e.g., the pressing of a button on a keyboard), it transitions from the lower-power mode back to the active mode.
Many of these portable electronic devices include one or more communication interfaces for transferring data to and from software applications running on the device. For example, a PDA may include one or more wireless communication interfaces such as a wireless peer-to-peer-area-network (WPAN) interface that operates according to the Bluetooth standard, a wireless local-area-network (WLAN) interface that operates according to the IEEE 802.11 standard, or a wireless wide-area-network (WAN) interface that operates according to the GPRS standard.
Unfortunately, a portable electronic device having multiple communication interfaces may not always transfer data via the interface that consumes the least power
Another problem with such a portable electronic device is that if the interface transferring the data becomes unavailable (e.g., loses signal), then the operator of the device typically must wait until the interface becomes available or must manually select another interface that is available to continue the data transfer.
Yet another problem with such a portable electronic device is that it may have multiple communication interfaces turned on simultaneously while the device could consume significantly less power by using fewer interfaces, or a single interface, to transfer the data.